Question

I have this query here

SELECT a.FileTrackingTag, a.DataSetName FROM TempTable a
LEFT JOIN FinalTable b ON a.Title = b.Title
WHERE b.FileTrackingTag IS NULL
AND b.DataSetName IS NULL

And I want to update the Filetrackingtag and the datasetname in finaltable with the values in temptable only if they are null and having the same Title and SampleID between the two tables

table structure is as such,
both tables have Title, Filetrackingtag, and Datasetname

Any recommendations?

Answer 1

I think the statement you’re looking for is this:

UPDATE f SET
    Filetrackingtag = isnull(f.Filetrackingtag, t.Filetrackingtag),
    Datasetname  = isnull(f.Datasetname, t.Datasetname)
FROM FinalTable f
JOIN TempTable t 
    ON f.Title = t.Title and f.SampleID = t.SampleID

(I haven’t tested the code, but I’m pretty confident it should work)